All accuracy data were arcsine transformed to improve normality. For RT tasks, we applied a within-subject trimming procedure recommended by Wilcox and Keselman (2003) before computing mean RTs. Then, to reduce the influence of extreme scores and improve normality, for each variable, we replaced observations farther than three standard deviations from the group mean with values three standard deviations from the mean. There were no significant age or sex effects for executive function measures, except for a small but significant sex difference in antisaccade scores. The measures were transformed to z scores so that the variance of each measure would be comparable to the behavioral disinhibition measures.
